Electric furnace and electrode mechanism therefor



Aug. 15, 1939. w, E MOORE 2,169,808

ELECTRIC FURNACE AND ELECTRODE MECHANISM THEREFOR Original Filed Jan. 31, 1936 2 Sheets-Sheet 1 Aug. 15, 1939. r w MOORE 2,169,808

ELECTRIC FURNACE AND ELECTRODE MECHANISM THEREFOR Original Filed Jan. 31, 1936 2 Sheets-Sheet 2 f ing this invention,

Patented 15, l 939 PATENT OFFICE Emcnrc mimics m IllglBoDl Willi EM M Pa l-inertia mar... rum :1, 1m, Serial No.

um am 1 61,810. Divided and 11, 1937, Serial Na n.

The present invention relates to improvements in furnaces and more particularly to electric furnaces of the type used in metallurgical operations although not necessarily restricted to this use.

An important object of this invention is the provision of an electric furnace for metallurgical operations which. can be made in any size or capacity but which is particularly well adapted for the smallercapacity furnaces, being inexpensive to produce and to operate. Small furnaces of this type having a capacity of one-half to one and a half tons, for example, can be run at a very low demand cost whereas large furnaces require a large demand cost when operated at low tonnages in times of reduced output. The furnace of'the present invention may be made in small sizes to be operated in conjunction with a large furnace, as a bleeder unit or for operation with its own substation as a separate melting. furnace. f Another object of this invention is theprovision of an electric furnace which takes up a minimum of space, which is and durable, and which tion.

Other objects and advantages of this invention will be apparent during the course of the follow! ing description. V

This application is a division of my c'o-pending application No. 61,810 filed, January 31, 1936 for Electric furnaces.

In the accompanying drawings, which form a part of this specification and wherein like charis economical in operaacters of reference denote like parts throughout;

Figure l is an elevation of a furnace embody- .Flgure- 2 is a top plan view of the furnace, Figure 3 is a side elevation of the electrode supporting column, parts being broken away,

- Figure 4 is an end elevation of one of the swiveling cuffs connecting an electrode arm to one of the electrode supporting columns,

Figure 5 is a side elevation thereof.

Figure 6 is a side elevation of a modified form of one of the electrode supportingcolu'mns in position on the furnace and showing th'e hoisting gear in place,

Figure 7 is an elevation of the hoisting gear at right angles to Figure 6, parts being broken away, 7 amid-end and-support the electrode arms 30,

insulated therefrom. The columns may tionswith respect to the electrode supportfiig column which is shown in section.

easily operated, strong scum-((11:44)

Figure 9 is a longitudinal sectional view of one of the guide rollers,-

Figure 10 is a side elevation of an eccentric shaft for adjusting the guide roller,

Figure 11 is an end elevation thereof on a somewhat larger scale, and,

Figure 12 is a side elevation of one of the electrode columns showing another position of the hoisting mechanism with respect thereto.

In the accompanying drawings, wherein for the purpose of illustration is shown a preferred embodiment of this invention, the numeral l5 designates the crucible shell ofa furnace embodying this invention. This shell may be of plate steel and cylindrical in sliape with a flat bottom 16 also of plate steel welded to the inner wall of the shell. A bezel ring ll surrounds the top of the furnace shell to strengthen the shell. A door It and a tapping spout l9 permit operation of the furnace and inspection of. the interior of the V on the furnace crucible and may be lifted by means of suitable loops 24 arranged at the top of ring 22. Four brackets 25 are secured to the top of the bezel ring l1 and are-each'provided with a centering bolt 28 to engage the outer periphery of the roof ring. By adjusting the bolts 20 the furnace roof may be properly centered inplaoe upon the top of the crucible.

The electrodes 21 are carried by suitable water cooledclamps 2! of electrically conducting material such as copper. Water circulating pipes- 29 carry cooling water to and from the clamps 2B.

The electrode arm II is preferably in the form of an H-beam. The arm 30 may be of any other desired cram-section and if desired, may be of electrically conducting material such ascopper or brass. It is preferred, however, to form the of'steel to give the necessary strength forarm a y the electrode, and to reinforce the arm with copper or other-electrically conducting bars 3| placed within the flanges of the arm and bolted thereto. The electric current is conducted to the clamps Ilbybarsil.

Electrode columns 32 are arranged to be raised beef any suitable cross-section such as a simple .H-be'a'm', or'theH-beam may be boxed in, as indicated in'l'lgure 8, for greater strength. A recu 20 crucible, and a tilting mechanism 20, which may be power or hand operated, is arranged to tilt indicated in Figure 4. A pair of set screws 36 isarranged at each end of the platform 33 for a purpose to be hereinafter described. A substantially inverted U-shaped hood 31 has thickened lower edges provided with central openings to receive a pivot pin 38 adapted to extend through sleeve 35 and to be secured by means of cotter keys 39 or the like. The hood is pivotally secured to the platform 13 by means of pivot pin 38.

The arm 30 is adapted to extend through the pivoted hood 3? and is insulated and spaced from the hood and from the platform 33 by means of insulating strips 40 of asbestos or the like and pieces 4| of suitable board such as ebony board, as shown in Figure 4. Additional boards or strips of wood or other'suitable material may be arranged above or below the arm 30 and insulating i material or at the sides thereof to fill up any space between the insulating material and the walls of the hood, if desired. By tightening up on bolts or'set screws 36 the arm 30 is securely clamped in the hood. The pivoted hood 3'! asconnected to a source of electric current by suit-- able conductors 3!. By using the pivoted hood 3'! and screws 36, the arm is forced into intimate engagement with the top of the hood. Due to the pivoting of hood 31, it will be adjusted to the position ofarm 30, so that the arm will engage the hood throughout the entire length of the hood. This engagement is not dependent upon the proper setting of the screws 36' but results from. the pivoted -mounting of the hood and the pwition of the screws 36 on the platform or column. While the screws 36 control the angular position of arm 30, the proper relation of the hood and arm is assured by the pivotal mounting of the hood irrespective of the setting of the screws 36.

The columns 32 are each adjustable vertically V to raise and lower the electrodes, and are guided by suitable rollers 42 and (supported by upper and lower brackets 43 secured to the furnace shell 7 l5. Each of the rollers comprises a pair of adjustably spaced roller members '44 held apart by the column 32 and rotatably mounted on shaft 45 which in turn is secured to suitable brackets 46 by adjusting nuts l1. and set screws 66, as indicated in Figure 3. The roller bearings l6 niay be provided to reduce friction. The rollers 42' which.

are moutned on opposite sides of the columns 32 .are preferably adjustable transversely of the roller axis, as well as longitudinally thereof. The transverse adjustment may be obtained by forming the roller shaft 45' with aneccentric body portion 50, to receive the roller members 44. as

shown in Figures 10 and 11. Adjustment of the and one which places them out of the operator's way. If desired, however, these winches maybe located on the upper of the brackets l3,'as indicated in Figure l2. Each of the winches consists 'ment and centering of the roof.

shaft 52 on which a worm gear 53. is mounted. A worm 54 engages worm gear 53 and is mounted on a horizontal shaft 54 arranged at a right angle to shaft 52 and which extends through the casing 5|. A relatively large gear wheel 55 is mounted to turn with the worm shaft 54 exteriorly of the casing 5i. A small pinion gear 56 meshes with large gear 55 to rotatethe large gear and is in turn operated by a suitable electric motor 51 mounted on a platform 58 which may be formed integrally with the top of casing 58. A suitable handle 59 may be connected to the large gear wheel 55 for manual rotation thereof.

Worm gear shaft 52 extends outwardly beyond casing 5| in which it is journaled and passes in proximity to column 32. A suitable reel 60 is mounted on shaft 52'to turn therewith and a cable 6! is wound on reel 60 and is connected at its end to the lower end of column 32 as indicated in Figure 6. Preferably reel 60 is arranged in contact with the column and has its sides pro vided with radially extending annular flanges 62 adapted to extend past the edges of column 32 so that reel 60 serves as a roller-to engage the column, as indicated in Figures 6, 7 and 8;

The winch motors 51 are preferably used for raising and lowering the electrode columns, but

this movement may also be effected by use of the Figures 6, 7, 8 and 12 to take the place of one,

of the rollers on each column and engage and .guide the rear edge of the column. In this position,'-the'reels and winches are disposed at an angle of 90 degrees from the position shown in Figures 1 and 2. V

The use of the pivoted cuffs 37 assures a secure connection between arms 30 and columns 32 while the set screws 26 permit a ready adjust- The columns 32' and which mechanism are supported by the furnace shell and tilt therewith, while the winch construction employed dispenses with the necessityfor numerous pulleys for operating the electrodes.

While the preferred embodiment of the inventlon has been shown and described, it is to be understood that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. In afurnace of the character described, a' furnace crucible, an electrode extending into said crucible, an electrode arm to support said electrode, a column carried by the crucible, a platform at the top of said column and adapted to support-said electrodearm, a hood pivotally connected tothe column and extending over the electrode arm, a. clamping member carried by the platform and adapted to clamp the arm against the pivoted hood, and means to insulate the arm from the platform and hood.

2. In a furnace of the character described, a furnace crucible, an electrode extending into said crucible, an electrode arm to support said electrode, a bracket supported by the furnace crucible, a column slidably engaging said bracket and operatively eng ng said electrode arm to raise and lower the arm and electrode, a column raising and lowering mechanism operatively engaging said column and supported by said bracket, 5 said raising and lowering mechanism comprising a drum, a cable wound on the drum and secured tothe column, and an electric motor operative- -ly connected to the drum, said drum having an annular portion arranged in contact with the 10 column to serve as a guide roller therefor.

. 3. Ina furnace of the character described, a furnace crucible, an electrode extending into said crucible, an electrode arm to support said electrode, a bracket supported by the furnace cruci- 15 ble, a column secured to said electrode arm, a

guide member carried by the bracket and engaging one side of said column, a rotatable reel supported by said bracket and having a guide portion engaging the opposite side of said column, 20 means carried by said reel and operatively engaging the column to raise and lower the column when the reel is rotated, and means to rotate said reel.

4. In a furnace of the character described, a

furnace crucible, an electrode extending into said crucible, an electrode arm to support said electrode, a bracket supported by the furnace.

crucible, a column secured to said electrode arm, a guide member carried by the bracket and enso gaging one side of said column, a rotatable reel supported by said bracket and having guide portion engaging the opposite side of said column, means can'ied by said reel and operatively engaging the column to raise and lower the column when the reel is rotated, and means torotate said reel, said guide member being adjustable toward and away from the column.

5. In a furnace of the character described, a furnace crucible, an electrode extending into said crucible, an electrode supporting column, a

bracket carried by said furnace crucible, a reel supported by said bracket and carrying a member to engage the column and raise and lower the column when the reel is rotated, an annular guide member'carried by said reel and engaging the column, means to rotate the reel, and a roller carried by said bracket and engaging the column on the opposite side thereof.

8. In a furnace of the character described, a furnace crucible, an electrode extending into said crucible, an electrode supporting column, a bracketcarried by said furnace crucible, a reel supported by said bracket and carrying a member to engage the column and raise and lower the column when the reel is rotated, an annular guide member carried by said reel and engaging the column, means to rotate the reel, and agroller carried by said bracket and engaging the column on the opposite side thereof, said roller being adjustable toward and away from the column.

WILIIAH I. MOORE. 

